Blockchain Data · x402

Base token change report: compares signed, seven-day baselines with block-pinned owner,…

Base token change report: compares signed, seven-day baselines with block-pinned owner, pause, proxy and supply reads, plus optional same-pool token balances. Returns field-level evidence and unknowns. No honeypot simulation, sell-tax estimate, USD liquidity…

by Saylor Innovations Knowledge Base · verified provider · updated 2026-10-15

30d calls—

30d payers—

MethodPOST

Outputjson

What it does

Capabilities

detect owner or pause changes
track proxy upgrades
compare supply and fixed-pool balances

Tags: base · token · monitoring · onchain · risk-changes

Call contract

Method: POST
Input: json
Output: json

Input example from Bazaar metadata

{
  "address": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913"
}

Output example

{
  "schema_version": "token-risk-changes/1",
  "status": "baseline_created",
  "current": {
    "chain": "eip155:8453",
    "address": "0x833589fcd6edb6e08f4c7c32d4f71b54bda02913",
    "pool": null,
    "block": {
      "number": "40000000",
      "hash": "0xabababababababababababababababababababababababababababababababab",
      "timestamp": "2026-10-14T00:00:00.000Z",
      "tag": "safe"
    },
    "observed_at": "2026-10-14T00:01:00.000Z",
    "fields": {
      "paused": {
        "value": false,
        "status": "observed",
        "evidence": {
          "method": "eth_call",
          "contract": "0x833589fcd6edb6e08f4c7c32d4f71b54bda02913",
          "input": "paused()"
        }
      }
    }
  },
  "previous_block": null,
  "changes": [],
  "coverage": {
    "compared": [],
    "not_compared": [
      {
        "field": "code_hash",
        "reason": "no_baseline"
      },
      {
        "field": "owner",
        "reason": "no_baseline"
      },
      {
        "field": "paused",
        "reason": "no_baseline"
      },
      {
        "field": "total_supply_raw",
        "reason": "no_baseline"
      },
      {
        "field": "decimals",
        "reason": "no_baseline"
      },
      {
        "field": "implementation",
        "reason": "no_baseline"
      },
      {
        "field": "admin",
        "reason": "no_baseline"
      },
      {
        "field": "beacon",
        "reason": "no_baseline"
      },
      {
        "field": "beacon_implementation",
        "reason": "no_baseline"
      },
      {
        "field": "legacy_implementation",
        "reason": "no_baseline"
      },
      {
        "field": "implementation_code_hash",
        "reason": "no_baseline"
      }
    ],
    "unavailable": [],
    "unsupported": []
  },
  "limitations": [
    "Contract-reported fields and standard proxy slots are not a complete security audit; zero slots do not rule out other upgrade mechanisms or privileged roles.",
    "Sellability, transfer taxes, blacklist behavior and transaction simulation are not tested. No safety or investment recommendation is made.",
    "Pool token balances are not reserves, active liquidity, USD valuation or proof of liquidity withdrawal. Swaps, rebases and transfers also change them.",
    "Only observations at the two stated blocks are compared; intermediate changes may be missed. Pool identity is caller-selected and DEX authenticity is not verified."
  ],
  "baseline": "EXAMPLE_ONLY_NOT_A_VALID_BASELINE",
  "baseline_expires_at": "2026-10-21T00:01:00.000Z"
}

Use with an agent

Discover. Agents find this listing with GET https://bazaar.saylorinnovations.com/discovery/search?query=…, the MCP tool search_resources, or /discovery/resources.
Inspect. Fetch /resources/saylorinnovations-api-base-token-risk-changes.json for the price and payment options.
Pay. Call GET https://saylorinnovations.com/api/base/token-risk/changes. The provider answers 402 with its payment requirements. An x402 client signs one of the options below and retries with PAYMENT-SIGNATURE.
Execute. The provider returns 200 with the data. Agent Bazaar is not in the request path and never sees your payment.

For humans

You don't need an account or an API key; you need a wallet holding a small amount of USDC on Base, and an x402-capable client (see the examples below). Call the endpoint unpaid first to see exactly what it asks for.

Pricing & payment

Price: $0.02 / request
Protocol: x402 v2
Auth: No account or API key. Pay per request.
Networks: Base

x402 payment requirements

Scheme	Network	Asset	Amount	Pay to	Timeout
exact	Base eip155:8453	USDC	$0.02	0xA2A8dF0f7CaaBEa4e120a2568118f141569fc8aa	120s

accepts[] (raw JSON)

[
  {
    "scheme": "exact",
    "network": "eip155:8453",
    "payTo": "0xA2A8dF0f7CaaBEa4e120a2568118f141569fc8aa",
    "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
    "amount": "20000",
    "amountUsd": 0.02,
    "maxTimeoutSeconds": 120
  }
]

Schemas

Output schema (JSON Schema)

{
  "type": "object",
  "required": [
    "schema_version",
    "status",
    "current",
    "previous_block",
    "changes",
    "coverage",
    "baseline",
    "baseline_expires_at",
    "limitations"
  ],
  "properties": {
    "schema_version": {
      "const": "token-risk-changes/1"
    },
    "status": {
      "enum": [
        "baseline_created",
        "changes_detected",
        "no_observed_changes",
        "insufficient_evidence"
      ]
    },
    "current": {
      "type": "object",
      "required": [
        "chain",
        "address",
        "pool",
        "block",
        "observed_at",
        "fields"
      ],
      "properties": {
        "chain": {
          "type": "string",
          "const": "eip155:8453"
        },
        "address": {
          "type": "string"
        },
        "pool": {
          "type": [
            "string",
            "null"
          ]
        },
        "block": {
          "type": "object",
          "required": [
            "number",
            "hash",
            "timestamp",
            "tag"
          ],
          "properties": {
            "number": {
              "type": "string"
            },
            "hash": {
              "type": "string"
            },
            "timestamp": {
              "type": "string"
            },
            "tag": {
              "const": "safe"
            }
          }
        },
        "observed_at": {
          "type": "string"
        },
        "fields": {
          "type": "object",
          "additionalProperties": {
            "type": "object",
            "required": [
              "value",
              "status",
              "evidence"
            ],
            "properties": {
              "value": {
                "type": [
                  "string",
                  "number",
                  "boolean",
                  "null"
                ]
              },
              "status": {
                "enum": [
                  "observed",
                  "unsupported",
                  "unavailable"
                ]
              },
              "evidence": {
                "type": "object",
                "required": [
                  "method",
                  "contract",
                  "input"
                ],
                "properties": {
                  "method": {
                    "type": "string"
                  },
                  "contract": {
                    "type": "string"
                  },
                  "input": {
                    "type": "string"
                  }
                }
              }
            }
          }
        }
      }
    },
    "previous_block": {
      "type": [
        "object",
        "null"
      ]
    },
    "changes": {
      "type": "array",
      "items": {
        "type": "object",
        "required": [
          "field",
          "before",
          "after",
          "attention"
        ],
        "properties": {
          "field": {
            "type": "string"
          },
          "before": {
            "type": [
              "string",
              "number",
              "boolean"
            ]
          },
          "after": {
            "type": [
              "string",
              "number",
              "boolean"
            ]
          },
          "attention": {
            "enum": [
              "review",
              "informational"
            ]
          },
          "delta_raw": {
            "type": "string"
          },
          "change_percent": {
            "type": [
              "number",
              "null"
            ]
          }
        }
      }
    },
    "coverage": {
      "type": "object",
      "required": [
        "compared",
        "not_compared",
        "unavailable",
        "unsupported"
      ],
      "properties": {
        "compared": {
          "type": "array",
          "items": {
            "type": "string"
          }
        },
        "not_compared": {
          "type": "array",
          "items": {
            "type": "object",
            "required": [
              "field",
              "reason"
            ],
            "properties": {
              "field": {
                "type": "string"
              },
              "reason": {
                "type": "string"
              }
            }
          }
        },
        "unavailable": {
          "type": "array",
          "items": {
            "type": "string"
          }
        },
        "unsupported": {
          "type": "array",
          "items": {
            "type": "string"
          }
        }
      }
    },
    "baseline": {
      "type": "string"
    },
    "baseline_expires_at": {
      "type": "string"
    },
    "limitations": {
      "type": "array",
      "items": {
        "type": "string"
      }
    }
  }
}

Example shape — generated from the schema, not a captured live response

{
  "schema_version": null,
  "status": "baseline_created",
  "current": {
    "chain": "string",
    "address": "string",
    "pool": "string",
    "block": {
      "number": "string",
      "hash": "string",
      "timestamp": "string",
      "tag": null
    },
    "observed_at": "string",
    "fields": {}
  },
  "previous_block": {},
  "changes": [
    {
      "field": "string",
      "before": "string",
      "after": "string",
      "attention": "review",
      "delta_raw": "string",
      "change_percent": 0
    }
  ],
  "coverage": {
    "compared": [
      "string"
    ],
    "not_compared": [
      {
        "field": "string",
        "reason": "string"
      }
    ],
    "unavailable": [
      "string"
    ],
    "unsupported": [
      "string"
    ]
  },
  "baseline": "string",
  "baseline_expires_at": "string",
  "limitations": [
    "string"
  ]
}

Examples

curl

curl -X POST 'https://saylorinnovations.com/api/base/token-risk/changes' -H 'Content-Type: application/json' --data '{"address":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913"}'
# -> 402 Payment Required; read PAYMENT-REQUIRED
# retry the identical request with PAYMENT-SIGNATURE

JavaScript

const res = await fetch("https://saylorinnovations.com/api/base/token-risk/changes", {
  "method": "POST",
  "headers": {
    "content-type": "application/json"
  },
  "body": "{\"address\":\"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913\"}"
});
if (res.status === 402) {
  const { accepts } = await res.json();
  // pay one of accepts[] via an x402 client, then retry with the payment header
}

Python

import httpx
import json
res = httpx.request("POST", "https://saylorinnovations.com/api/base/token-risk/changes", json=json.loads("{\"address\":\"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913\"}"))
if res.status_code == 402:
    accepts = res.json()["accepts"]
    # pay one of accepts[] via an x402 client, then retry with the payment header

Details

Provider: Saylor Innovations Knowledge Base
Endpoint: https://saylorinnovations.com/api/base/token-risk/changes
Side effects: Paid calls settle the advertised payment; see the provider contract for execution behavior.
Machine-readable: /resources/saylorinnovations-api-base-token-risk-changes.json